Well, perhaps I can help you out a bit.
I made a Github template to use when starting a new app that is to support Zigbee Light Devices using SDK3 (firmware 5) and everyone are free to use it!
Template:
Instructions: Zigbee_Light_Device_Template/template_instructions.txt at master ยท JohanBendz/Zigbee_Light_Device_Template ยท GitHub